Regional analgesia can often be extremely beneficial for elderly pa¬tients. One advantage of regional techniques is Ihe reduced amount of narcotic needed. The disadvantages include (he hemodynamic changes associated with epidural local anesthetics and the potential for intravas¬cular injection, infection, bleeding, and nerve damage. When a regional anesthetic block is performed before a painful stimulus Ue, surgery) is initialed, pain relief lasts longer than would be expected from the pharmacokinetics of the local anesthelic. When the pain does recur, it is less intense, and lower doses of narcotic can be used. The mechanism for this phenomenon appears to occur at the spinal cord level and in¬volves modulation of the impulses eventually received in the brain.
Regional analgesic techniques range in complexity from instillation of local anesthelic into the surgical incision lo specific nerve blocks to continuous epidural infusions of local anesthetic, a narcotic, or a com¬bination of the two. The choice of technique depends on the surgical site and the relative complexity and potential advantages or disadvan¬tages of a particular technique.
Pain relief after limb surgery is often accomplished with a single-dose nerve block or a continuous infusion. For hand and elbow procedures, the axillary approach is used to block the brachial plexus because this approach can be used with relative ease and it has a lower incidence of complications than the other approaches to this plexus have, if a need for prolonged analgesia is anticipated, a catheter is inserted and an infu¬sion of local anesthetic is begun postoperatively. Often an infusion of bupivcicainc 0.125% is sufficient for complete pain relief. The infusion rate is usually started at X to 10 mL/h and titrated to desired effec¬tiveness.
After knee procedures, a continuous femoral sheath catheter tech¬nique can be used. Although the sciatic nerve is not blocked with this approach, patients still receive adequate analgesia. The femoral cathe-ler infusion may be supplemented by low-dose narcotics or ketorolac. For both the axillary and femoral sheath blocks, a blunt tip needle may be used. The same needle may be used for both single-dose and contin¬uous infusion techniques. The distinct pop felt when the needle enters the sheath signals an excellent end point for proper needle placement. This pop is much more evident with the blunt needles than with the traditional B-bevel needles. Also, with the blunt needles, entering the adjacent artery is more difficult, and the incidence of nerve damage is decreased.
Epidural analgesia: After hip. abdominal, or (horacic procedures, a continuous epidural technique is often used for analgesia. An infusion of bupivacaine 0.125% to 0.0625% solution containing fentanyl 4 to 5

usually provides excellent analgesia. When the epidural cathe¬ter is placed at the dermatome level where discomfort is perceived, the amount of local anesthelic and narcotic can be reduced, minimizing (he possibility of toxicity. For hip procedures, a lumbar, epidural catheler placement is used; for abdominal procedures, a low-thoracic, epidural catheter placement is used; and lor thoracotomies, a niidthoracic, epi¬dural catheter placemen! is used. Fenlanyl is lipophilic and does not spread widely in the epidural space, so the catheter must be placed close to the segmental area of Ihe lesion. The need for precise catheter placement can he circumvented by using epidural morphine, which spreads more readily in the epidural space. However, the rostral spread of morphine may result in late respiratory depression.
The most common complication is inadvertent removal of the cathe¬ter during routine nursing care. Meticulous taping of Ihe catheter and nursing education can reduce (his problem. Urinary retention second¬ary to the local anesthetic and Ihe narcotic occurs and is more prevalent in elderly men. Migration of the catheter to the subcutaneous tissues or the spinal space can also occur. The former results in a lack of pain relief; the latter can result in disastrously high spinal anesthesia. Fortu¬nately, the latter rarely occurs.
In an elderly patient, an epidural infusion must be titrated precisely, and intravascular volume must be maintained by close monitoring of fluid status. Blood loss of 300 lo 500 ml, from a hip wound drain can result in severe hypotension in an elderly palient with a sympathetic blockade if volume resuscitation is nol promptly instituted.
Posloperalive pain control in the elderly patient is best accomplished by a dedicated, functioning pain control service. Strict attention to the patient’s hemodynamic parameters and mental status along with a thor¬ough understanding of the altered effects of various medications in the elderly are essential. Cooperation between the surgical, nursing, and pain service staffs can provide safe and effective analgesia for even the most frail elderly patient.